Whether a cancer survivor is eligible to donate blood depends on many
factors. Policies can vary from one blood donation center to the next
and from country to country.

The main considerations are as follows:

Potential for harm to the donor. Most blood donation centers
will require cancer survivors to obtain a letter from their oncologist
saying that it is ok for them to give blood.

Blood quality. No blood donations are accepted from
patients with a history of hematological cancer (i.e., where the
cancer affected blood cells), such as leukemia, lymphoma, Hodgkin's Disease, Mycosis Fungoides, Kaposi's Sarcoma, Multiple Myeloma, and Polycythemia Rubra Vera.
Blood may also be refused from cancer
patients who underwent a splenectomy or certain types of transplants,
or who had cancer affecting any organ in the blood production system
(e.g., liver cancer).

Drug pharmacokinetics. No blood donations are accepted
from patients undergoing active treatment. Most centers will require
that at least 5 years have passed since the end of therapy, and some
will require at least 10 years. A key issue is the type of
chemotherapy, and whether enough time has passed for residual amounts
to drop significantly below therapeutic levels. (The last thing the
blood bank wants is for the blood donation to induce neutropenia or
anemia in the blood recipient.) Generally, for non-teratogenic drugs,
5 plasma-elimination half lives (i.e., approximately 3% of therapeutic
levels) is considered safe. For teratogenic drugs, 28
plasma-elimination half lives is considered safe. But it can also
depend on the original dose; an additional safety margin may be
required for survivors who underwent high dose chemotherapy. It also
depends on the type of chemotherapy; cisplatin and other heavy metals, for example, can
persist in serum for decades.

Beyond the FDA's minimal requirements, each blood donation center sets
its own guidelines.

The current
Red Cross blood donor eligibility guidelines
require that at least five years have passed since the end of
treatment without any relapses. Exceptions include leukemia and
lymphoma, for which donations are never accepted, and low risk cancers
(e.g., squamous or basal cell cancers of the skin), for which a five
year waiting period is not required.

(Prior to July 21, 2003, the Red Cross's guidelines prohibited blood
donations from any cancer patients treated with chemotherapy,
hormone therapy or immunotherapy, even if
they were more than five years past the end of treatment. Many blood
donation centers continue to adhere to the former guidelines. For
example, Dana
Farber will not accept blood donations from cancer survivors,
regardless of the treatment methodology and the number of years since
the end of treatment.)

In the UK, blood donations are not accepted from cancer survivors, no
matter how many years have passed since the end of treatment.

As an alternative to donating blood yourself, you can always encourage
friends and family to donate blood on your behalf. Such appeals are
especially effective from current cancer patients. Many of your
acquaintances want to do something to help. Even if you aren't going
to need blood yourself, their donations will help others.